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Crucial shuttle fragments may never be found

By Jeff Hecht

The doomed space shuttle Columbia was shedding debris as it flew over California, NASA confirmed on Tuesday, but these crucial first pieces may never be found.

No fragments have yet been recovered the west of Texas, the state over which the shuttle disintegrated. Jim Hallock, a member of the Columbia Accident Investigation Board, said the material that came off over California did not appear to have been very large pieces, so they probably burned up in the atmosphere.

To survive the descent to the ground, debris would have “to be a pretty substantial piece of the shuttle itself”, he told a press conference at the Johnson Space Flight Center in Houston.

About 2600 pieces of Columbia have “identified, catalogued, and laid out on the floor” at the Kennedy Space Flight Center in Florida, said panel head Harold Gehman. More than 1000 additional pieces have been delivered to Kennedy but are not yet identified, and some 10,000 more are being collected and processed.

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The pieces come from all parts of the spacecraft. But based on weight, “right now we have a tiny, tiny fraction of the orbiter,” Gehman said. More debris is vital to the panel’s investigation, he added.

Hawaiian photographs

The US Air Force did photograph Columbia’s flight even earlier, over Hawaii. The images were taken with the 3.7-metre Maui Space Surveillance System, the largest telescope the Pentagon publicly acknowledges operating on the ground.

However, Gehman said&colon; “We didn’t see anything that jumped out at us, but it’s early in the process.” The telescope should be able to resolve 10-centimetre-sized details, depending on the shuttle’s distance.

The panel is also taking a fresh look at possible damage to the left wing by material falling from the external fuel tank during Columbia’s launch.

NASA engineers thought the falling material was foam insulation, but the panel wants to check if it might have included ablative material underneath the foam, or ice, or even metal. The ablative material is heavier than the foam, and would have caused more damage, Hallock said.

Four thrusters firing

The press conference was also told that engineers have recovered some data from the first five seconds after Mission Control lost signals from the shuttle.

They show that the third and fourth thrusters on the right wing began firing, trying to offset increasing drag on the left wing.

Two other thrusters on the right wing had already been firing. Hallock said that was unusual, because all four thrusters do not normally fire simultaneously.